This invention relates to mercapto-C.sub.2 -C.sub.3 -alkanoic acid esters of citronellol, geraniol, homologues thereof and partially saturated derivatives thereof defined according to the generic structure: ##STR2## wherein N represents 0 or 1; M represents 0, 1 or 2; P represents 0 or 1; and the dashed line represents a carbon-carbon single bond or a carbon-carbon double bond with the proviso that when N is 0 then the dashed line represents a carbon-carbon single bond and uses thereof in augmenting or enhancing the aroma or taste of foodstuffs.
Artificial flavoring agents for foodstuffs have received increasing attention in recent years. In many areas, such food flavoring agents are preferred over natural flavoring agents at least in part, because of the uniform flavor that may be so obtained. For example, natural food flavoring agents such as extracts, essences, concentrates and the like are often subject to wide variations due to changes in quality and type and treatment of the raw materials. Such variations can be reflected in the end product and results in unreliable flavor characteristics and uncertainty as to consumer acceptance and cost. Additionally, the presence of the natural product in the ultimate food may be undesirable because of the increased tendency to spoil. This is particularly troublesome in convenience and snack food usage where such products as dips, soups, chips, prepared dinners, canned foods, sauces, gravies and the like are apt to be stored by the consumer for some time prior to use.
The fundamental problem in preparing artificial flavoring agents is that of achieving as nearly as possible a true flavor reproduction. This generally proves to be a difficult task since the mechanism for flavoring development in many foods is not understood. This is notable in products having hydrolyzed vegetable protein-like, roasted, sulfury, fruity, concord grape-like, grapefruit, blackcurrant, green, tomato and guava-like aroma and taste nuances.
Reproduction of roasted, sulfury, fruity, concord grape-like, grapefruity-like, blackcurrant-like, green tomato and guava aroma and taste nuances has been the subject of long and continuous searches by those engaged in the production of foodstuffs. The severe shortage of food, especially protein foods, in many parts of the world has given rise to the need for utilizing non-meat sources of proteins and making such proteins as palatable as possible. Hence, materials which will closely simulate or exactly reproduce the flavor and aroma of hydrolyzed vegetable protein and even blackcurrant, tomato, guava, grapefruit, roasted peanut and concord grape are required. Furthermore, meat flavors and vegetable flavors have been enhanced previously by the use of such materials as monosodium glutamate. In many diets, sodium is not desired. Furthermore, in many diets, the use of glutamate ion or glutamic acid is highly undesirable. Therefore, a need has arisen for a monosodium glutamate replacer and an alkali metal glutamate replacer which does not have any glutamate ion or any sodium ion present.
Moreover, there are a great many meat containing or meat based foods presently distributed in a preserved form. Examples of these are condensed soups, dry soup mixes, dry meat, freeze dried or lyophilized meats, packaged gravies and the like. While these products contain meat or meat extracts, the fragrance, taste and other organoleptic factors are often impaired by the processing operation and it is desirable to supplement or enhance the flavors of these preserved foods with versatile materials which have hydrolyzed vegetable protein-like and roasted aroma and taste nuances.
Food flavors in the thioalkanoic acid ester area are known in the art.
Thus, U.S. Pat. No. 4,426,403 discloses the genus of compounds defined according to the structure: ##STR3## wherein R and R' represent hydrogen or C.sub.1 -C.sub.3 alkyl as food flavorants, particularly in the fruity, vegetable or green pine needle aroma and taste area.
U.S. Pat. No. 3,870,800 relates to the processes for augmenting or enhancing the aroma or taste of foodstuffs using methylthio butanoic acid derivitives. U.S. Pat. No. 3,904,556, at Example XVII thereof states that ethyl-4-(methylthio)butyrate may be added to a cheese sauce to increase the notes usually present in the surface ripened cheese and to increase the cheese flavor intensity. In Example XX it is further stated that this compound, ethyl-4-(methylthio)butyrate is added to tobacco to enhance the pineapple character of a fruit flavor for tobacco.
U.S. Pat. No. 3,879,562 issued on Apr. 22, 1975 and the reissue patent thereof, U.S. Pat. RE No. 30,370 issued on Aug. 12, 1980 disclose the genus of compounds having the structure: ##STR4## wherein R.sub.1 represents alkyl, cycloalkyl, aryl, aralkyl, alkaryl, or alkenyl and R.sub.2 represents alkyl, alkyl thioalkyl, aralkyl, alkaryl, or aryl in augmenting or enhancing the aroma or taste of various foodstuffs.
McFadden, et al, Analytical Chemistry 37,560, have suggested the presence of methyl thiohexanoate and thioheptanoate in oil derived from hops, and Buttery, et al, have reported similar work in J. Chromatography 18,399. Schultz, Day and Libbey, "The Chemistry and Physiology of Flavors", Westport, Connecticut:Avi. Publishing Co. 1967, at page 412 disclose thioesters useful in flavoring.
Nevertheless, nothing in the prior art discloses the mercapto-C.sub.2 -C.sub.3 -alkanoic acid esters of citronellol, geraniol, homologues thereof and partially saturated derivatives of our invention or their unexpected, unobvious and advantageous uses in augmenting or enhancing the aroma or taste of foodstuffs.